THE IMPACT OF INTERLEUKIN-2 ON SURVIVAL IN RENAL-CANCER - A MULTIVARIATE-ANALYSIS

The purpose of this analysis was to compare the survival of patients w ith advanced renal carcinoma treated with intravenous recombinant inte rleukin-2 to the survival of matched patients taken from the large and well characterised database of the Eastern Cooperative Oncology Group (ECOG). Recombinant interleukin-2 (rIL-2) given by continuous intrave nous infusion was used to treat 387 patients with advanced adenocarcin oma of the kidney in five multi-centre studies and 327 of these patien ts fulfilled the study eligibility criteria and were evaluable for res ponse, toxicity and survival The survival of patients treated with rIL -2 was compared in a multi-variate survival analysis taking account of all identified prognostic factors to 390 control patients receiving c hemotherapy derived from the database. Thirteen patients treated with rIL-2 achieved a complete remission of their disease and 32 a partial remission giving an overall response rate of 14%. Remissions were dura ble with a median duration of 357 days for partial remissions and a me dian duration in excess of 926 days for complete remissions. Most pati ents experienced fever or mild to moderate hypotension and other toxic ities are described. However, only 11 patients required admission to i ntensive care and in only five cases was this judged to be due to trea tment toxicity. There were three deaths judged to be probably due to t reatment toxicity. rIL-2 treatment was associated with significantly p rolonged survival compared to the ECOG control patients. Patients with good prognostic features appeared to have a greater survival benefit from rIL-2 than those with poor prognostic features. This analysis pro vides the first evidence that rIL-2 prolongs survival in patients with advanced renal cancer but cannot provide proof which should be sought in randomised prospective trials drawing on the hypotheses generated herein.